Development of a hydrophilic polymer membrane containing silver nanoparticles with both organic antifouling and antibacterial properties

To obtain both organic antifouling and antibacterial properties, acrylamide was grafted onto a polyethersulfone (PES) hollow fiber membrane and silver nanoparticles were then formed within the acrylamide layer. The hydrophilicity of the membrane surface was improved by acrylamide grafting, leading to a reduction in membrane fouling by Bovine serum albumin. The silver nanoparticles were detected by X-ray photoelectron spectroscopy and transmission electron microscopy. Antibacterial activity of the silver-loaded membrane was evaluated against Escherichia coli (E. coli) using the halo zone test with an agar culture medium. The original PES membrane had no antibacterial activity and bacteria grew on the membrane surface, while clear halo zones were observed around the membranes containing silver nanoparticles, indicating high antibacterial activity. In addition, the antibacterial activity of the silver-loaded membranes was examined by immersing them in an E. coli suspension in a shake flask and incubating for 8 h at 37 °C. More than 99.999% of E. coli cells were killed, suggesting that the silver nanoparticles were quite useful for inhibiting bacterial growth. Thus, polymer membranes containing silver nanoparticles within the acrylamide gel layer were shown to have high potential for applications requiring both organic antifouling and antibacterial properties.

► The acrylamide grafting was effective for improving the membrane hydrophilicity.
► A high antibacterial property of the membrane containing Ag nanoparticles was confirmed.
► Membranes with both antifouling and antibacterial properties were successfully prepared.